To date many types of thermometers have been proposed. In particular, with the advent of nanotechnology, different techniques for measuring temperatures have been developed in very small length scales such as: scanning thermal microscopy (Scanning Thermal Microscopy—SthM—L. Shi, A. Majumdar, “Recent developments in micro and nanoscale thermometry”, Microsc. Thermophys. Eng. 2001, 5, 251-265), spectroscopy (Raman J. W. Pomeroy, M. Kuball, D. J. Wallis, A. M. Keir, K. P. Hilton, R. S. Balmer, M. J. Uren, T. Martin, P. J. Heard, “Thermal mapping of defects in AlGaN/GaN heterostructure field-effect transistors using micro-Raman spectroscopy”, Appl. Phys. Lett. 2005, 87, 103508), thermo-reflectance microscopy (thermo-reflectance microscopy—S. Dilhaire, D. Fournier, G. Tessier, “Microscale and Nanoscale Heat Transfer”, (Ed.: S. Volz), Springer-Verlag, Heidelberg, Germany 2007).
Several molecules have been proposed as luminescent molecular thermometers in a review of the series “Chemistry for Everyone” (S. Uchiyama, A. P. de Silva, K. Iwai, “Luminescent Molecular Thermometers: J. Chem. Ed. 2006, 83, 720-727).
The molecules so far reported in the literature show one or more of the following disadvantages.                small temperature range for their potential use (a few degrees Celsius);        sensitivity greater than a tenth of a Celsius degree;        reduced chemical and photochemical stability;        high cost of synthesis;        possibility to use only under certain conditions, for example, only in solution and/or only in solid form;        significant changes in behavior according to the conditions (for example, depending on the solvent in which the molecule is dissolved or if the molecule is in a solid or liquid state);        in the presence of oxygen the intensity of fluorescence decreases (which interferes with the proper functioning of thermometers that contain these molecules).        
In particular, note that some of the best molecules so far proposed have a sensitivity of about 0.5° C. (C. Gota, K. Okabe, T. Funatsu, Y. Harada, S. Uchiyama, “Hydrophilic Fluorescent Nanogel Thermometer for Intracellular Thermometry”, J. Am. Chem. Soc. 2009, 131, 2766-2767; C. Gota, S. Uchiyama, T. Yoshihara, S. Tobita, T. Ohwada, “Temperature-Dependent Fluorescence Lifetime of a Fluorescent Polymeric Thermometer, Poly(N-isopropylacrylamide), Labeled by Polarity and Hydrogen Bonding Sensitive 4-Sulfamoyl-7-aminobenzofurazan”, J. Phys. Chem. B 2008, 112, 2829-2836).
Recently, a class of zwitterionic metalates has been introduced and characterized. These metalates have been proposed as potential catalysts (R. Pattacini, L. Barbieri, A. Stercoli, D. Cauzzi, C. Graiff, M. Lanfranchi, A. Tiripicchio, L. Elviri, “Zwitterionic metalates of group 11 elements and their use as metalloligands for the assembly of multizwitterionic clusters”, J. Am. Chem. Soc., 2006, 128, 866-876; Cauzzi et al., “Coordination properties of the multifunctional S,N,S zwitterionic ligand EtNHC(S)Ph2P═NPPh2C(S)Net”, Coordination Chemistry Reviews 254 (2010) 753-764). No other potential use of these zwitterionic metalates has been proposed and, in particular, no study for the exploitation of their photophysical properties in relation to temperature was never made, suggested or even only hypothesized.
The aim of the present invention is to provide the use of a coordination complex for measuring temperatures and a device for measuring temperatures, which allow to overcome, at least partially, the problems of the state of the art and that are at the same time, of cheap and easy implementation.